Karl A. Gschneidner – författare

Even at the beginning of the new millenium the rare earths still remain, to a certain extent, a mystery. The chapters in this volume will help to unravel some of these. In the filling of the 4f electronic orbitals the lanthanides defy the elementary aufbau principle that underlies the periodic sequence of the elements, and the authors of the first chapter introduce the readers to the basic physics of the orbital collapse leading to that failure. Furthermore an explanation is offered in terms of double-well potentials. The phenomenon is illustrated using the valence transitions observed in some of the rare earth atoms, including Sm group metals and the higher oxides of cerium, praseodymium and terbium. In the second chapter the synthesis and structure of the many types of rare earth halides are described. They have been described as simple, complex, binary, ternary and multinuclear complex, and other categories needed to deal with the most studied of the rare earth compounds. The structure types are skillfully illustrated to show the elementary architecture of each type.In chapter three the authors discuss the science and applications of rare earth super ionic conductors as solid electrolytes. Conduction by oxygen and fluorine anions as well as hydrogen and other cations associated with these electrolytes is emphasized. They deal with extrinsic and intrinsic types together with their associated structures and structural types including structural defects. The chapter concludes with an outline of the many applications of solid electrolytes.Chapter four introduces the reader to the principles that underlie thermoluminescence and its application to dosimetry and provides detailed information on the R-activated phosphors that support dosimetry. This is a selective review of detailed literature based on the areas making most progress.The final chapter elaborates on the data gained by the studies and interpretation around the analytical separation of the individual rare earth elements utilizing chromatographic techniques. The authors describe the fundamental chemistry that underpins contemporary analytical separation techniques for lanthanide separation and analysis. This is done after a description of the rich assortment of separation methods in use has been introduced.

This continuing authoritative series deals with the chemistry, materials science, physics and technology of the rare earth elements in an integrated manner. Each chapter is a comprehensive, up-to-date, critical review of a particular segment of the field. The work offers the researcher and graduate student a complete and thorough coverage of this fascinating field. Authoritative Comprehensive Up-to-date Critical

The contributions to this volume focus on selected chemical aspects of rare-earth materials. The topics covered range from a basic treatment of crystalline electric-field effects and chemical interactions in organic solvents, to separation processes, electrochemical beaviors which impact corrosion, oxidation resistance, chemical energy storage and sensor technology, and to analytical procedures.

Underlying the most subtle chemical and optical properties of these elements and their compounds in the condensed state are the crystal field effects. This phenomenon in non-metallic compounds is discussed in chapter six. The volume opens with a review of important new solvent extraction procedures as well as emerging alternative separation processes such as photochemical separation, precipitation stripping and supercritical extraction. Scientific and industrial procedures are illustrated. In a further chapter eight major analytical techniques of obtaining accurate trace analysis are examined, tabulated and assessed. The most effective procedures of each are also reviewed. Chapter two considers a wide variety of methods using rare-earth solutions and slats to modify advantageously the costly deterioration of metals and alloys. This topic is expanded in the following chapter, paying particular attention to protection against high-temperature oxidation, sulfidization and hot-salt corrosion. The following two chapters are concerned with the versatility of the rare earths in addressing current technical problems such the use of rare-earth intermetallics, principally LaNi3-based materials, to provide the skyrocketing need for environmetally friendly, usually portable, battery power. The final chapter is a review of the solvation, interaction and coordination of rare-earth salts in a variety of organic solvents including dimethylacetamide, dimethylsulfoxide, various alcohols, acetonitrile and propylenecarbonate under strict anhydrous conditions. A contrast of these interactions with those in which water is present with organic solvents is also made.

This volume differs somewhat from the previous volumes in the series in that there is a strong emphasis on the physical aspects and not so much on the chemical aspects of intermetallic compounds. Two of the chapters are concerned with relatively new experimental methods of studying rare earth metallic phases - high energy neutron spectroscopy and light scattering. In these chapters the authors explain the new kinds of information one obtains from these techniques and how this complements the knowledge previously gleaned from the more common measurements - such as NMR, heat capacities, magnetic susceptibility, transport and elastic properties. One of the remaining three chapters deals with NMR studies of rare earth intermetallics and the final two chapters are concerned, not so much with a particular experimental technique, but with physical phenomena that occur in these compounds: the electron-phonon interaction and heavy fermion behavior.